Troubleshooting; Diagnosing Problems; Switch Post Results; Switch Leds - Cisco Catalyst C3850 Series Hardware Installation Manual

Table of Contents

Advertisement

Troubleshooting

Diagnosing Problems

The LEDs on the front panel provide troubleshooting information about the switch. They show POST failures,
port-connectivity problems, and overall switch performance. You can also get statistics from Device Manager,
from the CLI, or from an SNMP workstation.

Switch POST Results

POST failures are usually fatal. Contact your Cisco technical support representative if your switch does not
pass POST.

Switch LEDs

If you have physical access to the switch, look at the port LEDs for troubleshooting information about the
switch. See the LED section for a description of the LED colors and their meanings.

Switch Connections

Bad or Damaged Cable

Always examine the cable for marginal damage or failure. A cable might be just good enough to connect at
the physical layer, but it could corrupt packets as a result of subtle damage to the wiring or connectors. You
can identify this situation because the port has many packet errors or the port constantly flaps (loses and
regains link).
• Examine or exchange the copper or fiber-optic cable with a known, good cable.
• Look for broken or missing pins on cable connectors.
• Rule out any bad patch panel connections or media convertors between the source and the destination.
• Try the cable in another port or interface, if possible, to see if the problem follows the cable.
OL-26779-05
Diagnosing Problems, on page 107
Replacing a Failed Data Stack Member, on page 111
If possible, bypass the patch panel, or eliminate faulty media convertors (fiber-optic-to-copper).
7
C H A P T E R
Catalyst 3850 Switch Hardware Installation Guide
107

Advertisement

Table of Contents
loading

Table of Contents